Marrentill potions are used to create antipoisons. Because these are often used to train Herblore, and adding clean marrentill to a vial of water gives no experience, many players avoid the tedium of making unfinished potions and buy them directly from the Grand Exchange. This opens up an opportunity to make unfinished marrentill potions for profit. Like all methods involving large amounts of buying and selling, which require a relatively high capital to start, it is recommended to test the market by making one unfinished potion first to make sure they are profitable.

Withdraw 14 marrentill and 14 vials of water, and use one on the other. A menu will open, and click to Make-all. After the inventory is complete, you should be left with 14 unfinished marrentill potions. Deposit your inventory, withdraw 14 herbs and 14 vials of water, and repeat. Each inventory should take about 15 seconds with banking, which means you can make around 3,400 potions per hour.

Once you've finished making your potions, sell them on the Grand Exchange. Maximise your profit by buying one unfinished potion instantly, and selling all of yours for slightly less than that.

Due to constantly changing prices on the Grand Exchange, some information in this article may or may not be current.It is strongly recommended to check the live prices on the Grand Exchange before making large investments in any method.All prices on this page are cached, meaning it is possible that they appear out of date.To force a new cache of this page, click this link.If a money making method is out of date, you can edit it or leave a message on the talk page.